Radioimmunoassays have been developed for the detection and quantitation of trace amounts of bovin proteins (BGG, BSA, alpha-lactalbumin, beta-lactoglobulin and casein) in human serum and breast milk. In addition, the detection of antibodies to these substances is possible. Using fluoresceinated reagents these proteins and/or their specific antibodies can be detected in tissue. The purpose of the proposed study is to utilize these techniques in an investigation of the possibility that food antigens (as exemplified by these bovine proteins) can take part in the formation of pathogenic immune compexes in the circulation and deposit in the kidneys or other target organs, setting off an inflammatory process resulting in damage to the tissue. Results indicate that BGG and casein do enter the circulation and thus far, in two renal biopsies from individuals with chronic idiopathic glomerulonephritis, there appear to be immune complex deposits which contain BGG. During the coming year further tissue and sera will be studied and an attempt made to determine whether the circulating and/or deposited antigens are intact or digestion products. Other questions to be examined using the same techniques are 1) is bovine protein ingested by a lactating mother secreted into the breast milk as intact or digestion products and 2) is the difference between milk-sensitive individuals and those without clinical sensitivity but a positive skin test related to differences in absoprtion of milk from the GI tract. BIBLIOGRAPHIC REFERENCES: Carr, R.I., Hoffman, A.A. and Harbeck, R.J.: A comparison of DNA binding in the normal population, general hospital laboratory personnel and personnel from laboratories studying Systemic Lupus Erythematosus (SLE). Proc. UCLA Symposium on the Immunopathology of Nucleic Acids in the Rheumatic Diseases. J. Rheumatology 2:178, 1975. Carr, R.I., Harbeck, R.J., Hoffman, A.A., Pirofsky, B. and Bardana, E.J.: Clinical studies on the significance of DNA: anti-DNA complexes in the systemic circulation and in the cerebrospinal fluid (CSF) of patients with Systemic Lupus Erythematosus (SLE). Proc. UCLA Symposium on the Immunopathology of Nucleic Acids in the Rheumatic Diseases. J. Rheumatology 2:184, 1975.